KR20200016959A - Pressure vessel - Google Patents

Abstract

The present invention relates to a container containing a liquid and / or gaseous medium having or generating underpressure during transportation or storage. The cylindrical container cover 101 is made primarily of paper or cardboard based material and is closed at the bottom by the base element and at the top by the cover. The vessel can withstand an internal pressure of at least 5 bar. The innermost layer of the container cover 101 includes a straight wound barrier layer 102 having a fold that extends in itself and extends in the longitudinal direction of the container. Such barrier layer 102 is a laminate previously made of an inner diffusion hermetic barrier film or inner diffusion hermetic barrier laminate 108 and an outer kraft paper layer 107.

Description

Pressure vessel

The present invention relates to a pressure resistant vessel having a can shell made of a composite material.

A pressure resistant container is a container for packaging a medium having a static pressure or a medium which may occur during storage, transportation or use.

The present invention therefore relates to a fluid container, in particular a beverage container, which can also be used in gaseous canned beverages, such as carbonated mineral water, sweet drinks, energy drinks or beer, which are special beverages for pressure purposes. This is because it is sufficiently resistant. Depending on the design, it is suitable for all kinds of spray cans with much higher internal pressure. In addition, the present invention facilitates the filling of beverages using such beverage cans, and in particular, the cans of containers can be easily filled in the field and preferably can be produced at the same time preferably made of an existing filling plant (filling plant) It relates to a manufacturing and logistics method. This saves a lot of space and storage cost and is independent of empty containers. Preferably, conventional can fillers for the introduction of this new fluid container or beverage container do not need to modify the can filling plant, but can continue to be used smoothly. Their own can production is facilitated, and the space required for this is a small portion of the space required for storing the previously indispensable buffer of empty aluminum cans for subsequent filling.

According to current practice, aluminum cans are manufactured centrally at appropriate locations and emptied into various can fillers. It is important to carry a huge amount of empty containers and air around the landscape. In order to avoid bottlenecks when filling the filler, there should always be a sufficient quantity of empty containers, so a large warehouse should be maintained with sufficient space and corresponding capital input. Then fill the can into place and close the lid with filler.

In the packaging industry, multi-ply packaging is known to have paper or cardboard packaging wrappers whose individual plies are wound straight or at an angle with respect to the length of the mandrel and extend in the longitudinal direction of the packaging shell. It has joint areas with itself, extending jointly or spirally along the longitudinal direction of the packaging shell. These packages can have an inner barrier layer, which has a rigid folded seam at the joint area of the two edges. Cardboard and paper materials are generally used as the composite material of the layers. Such can shells have been used so far for general packaging purposes, for example for detergents, for powder packaging such as cocoa powder, or for snacks such as crisp crisps, in the case of food, the barrier layer is liquid from the outside. And protect the food from the ingress of gas and prevent the outflow of liquids and gases from the interior of the food or packaging shell.

On the other hand, there are many composite packages with can shells made of composites for food and beverages. However, they reach their limits in the field of compressive strength so as not to be used in compressed media, especially carbonated beverages. Although patent documents such as, for example, WO9959882 A9 and EP0101139 A2 have proposals for can shells made from composite materials for carbonated beverages, there has been no such product on the market so far. Perhaps the compressive strength could not be achieved sufficiently in the proposed can shells and / or finished cans, or because these proposed can shells and / or finished cans were not competitive with conventional beverage cans, in particular aluminum cans.

A disadvantage of the packages for carbonated beverages described in WO9959882 A9 is their special form, which on the one hand requires their own filling and sealing equipment and on the other hand deviates from the form of a beverage can which is familiar to consumers.

A disadvantage of the packages for carbonated beverages described in EP0101139 A2 is their special form, which on the one hand requires their own filling and sealing equipment and on the other hand in the area of beverage cans, especially the floor and cover, which are familiar to consumers. Depart from the form of.

A composite can for carbonated beverages is known from DE202007010192U1, the shell of which is mainly composed of paper or cardboard material, the wall thickness of which is given as 0.5545 mm. The disadvantage of DE202007010192U1 is that the shell consists of a thick sulfate board coated on both sides overlapping with itself, which creates a very wide section compared to the rest of the shell. Another disadvantage is that the inner edges of the laminate and the side edges of the outer edges are exposed and thus must be further sealed, for example by tape.

In WO2012155890A1, a carbonated beverage package having a shell made of a composite material is described, wherein the shell consists mainly of paper or cardboard material. The shell thickness (or layer thickness) of the composite shell of such cans is between 0.5 mm and 0.8 mm, and the thickness of the barrier film is between 50 μm and 120 μm. The disadvantage of WO2012155890A1 is that the sections are very widespread compared to the rest of the shell, since the entire laminate overlaps on its own. Another disadvantage is that the inner edge of the laminate and the side edges of the outer edge are exposed, for example to be further sealed by tape.

In US3687351 A1 a composite can for carbonated beverages is known, the shell consisting mainly of paper or cardboard material, the shell thickness being about 0.48 mm, which indicates that the layer structure comprises a thick aluminum layer with an approximately 25 μm layer thickness. It is disadvantageous in that point.

US4642252 describes a carbonated beverage packaging with composite shells, wherein the shell can be made primarily of paper or cardboard material. The shell thickness of the exemplary embodiment according to FIGS. 1, 8 and 9 is in each case about 900 μm, ie 0.9 mm. The disadvantage of US4642252 is that the innermost layer, ie the barrier layer, is spirally wound, which increases the length of its folded seam.

US4766019 proposes a can for carbonated beverages having a shell made of several layers of plastic. The shell thickness (or layer thickness) of the shell is 22 mils, or approximately 0.56 mm, in one typical embodiment. US 4766019 states that the shell thickness must be less than 30 mils (0.762 mm) so that the plastic shell can be closed with a conventional aluminum sheath. The disadvantage is that the shell is made entirely of plastic, so it is less sustainable. The innermost barrier layer in US4766019 protrudes on the mandrel.

US4181239A also shows a can with a plastic shell, in which case the disadvantage is that the can shell consists entirely of plastic layers. US4181239A states that such shell thickness should be between 85 μm and 770 μm, preferably between 100 μm and 400 μm.

It is clear from the prior art that it has been recognized that the can shell must not exceed a certain thickness so that it can still be closed with the standard aluminum can covers of conventional aluminum cans. Secondly, in can shells of at least several wound individual layers, it was clearly recognized that the can shell should not exhibit any large deviation in its layer thickness over the circumference. To achieve this, the innermost layer is designed as a laminate of thin plastic film or other plastic films and possibly aluminum foil, which can be obtained from US4181239A, US4766019 and US4642252. US4642252 also provides for a barrier laminate of plastic films and a spiral folded seam of aluminum foil being laminated by an intermediate paper layer.

In the case of paper or cardboard composite cans made of wound individual layers, paper or cardboard for use as a packaging for pressurized media and barrier laminates of plastic films and optionally aluminum foil for use as packaging of pressurized media, in particular carbonated beverages The hold between the next layer of material is found to be inadequate and disadvantageous, which can lead to damage, especially in the area of the fold seam, which can leak and eventually tear the can shell due to wetting of the paper or cardboard material. Or cause rupture.

It is an object of the present invention to provide a commercially available can shell made of composite material for press media, in particular cans for carbonated beverages, which can reliably withstand the dominant or possible internal pressures of such media and are mainly paper or cardboard Consists of materials. In addition, the fluid container has to be manufactured in a small and timely manner, with less space required locally at a locally low technology and energy cost in can filling operations, the production of which can optionally be combined with a filling plant in real time.

To achieve this purpose, cans containing liquid and / or gaseous media are proposed, which can have or create a static pressure during transport or storage, the cylindrical can shell of such cans consisting primarily of paper or cardboard material It includes at least two wound layers and is closed at the bottom with the bottom element, has a cover at the top, the can withstands internal pressure of at least 5 bar, and the innermost layer of the can shell is straight ) Can be made of a wound barrier layer, which comprises a folded seam that moves in the longitudinal direction of the can, the barrier layer being a laminate of an inner diffusion airtight film or inner diffusion airtight barrier laminate and an outer kraft paper layer, At least one additional wound paper or cardboard material layer is present around the barrier layer of the shell, the cardboard or paper surfaces and standing of the barrier layer. The wound layers made of paper or cardboard material laid on the furnace are attached to each other, in particular directly to each other.

Due to the fact that the innermost layer is wound upright, and because it is itself a straight folded seam and contains a stable layer of kraft paper, it is advantageous that this innermost layer, and especially the folded seam, have the necessary stability to withstand the high internal pressure of the can. Is achieved.

Due to the fact that the barrier layer is formed of a laminate of film and kraft paper, the film is relaxed in the folded seam region because the tension forces are derived from the kraft paper, and the tension forces advantageously act in the circumferential direction by the straight folded seam, No additional forces are introduced in the longitudinal direction of the can as in the case of spiral winding of the innermost layer or barrier layer.

Due to the fact that the innermost layer is made of paper material on the outside and the next layer is made of paper material, these two paper materials can adhere to each other, in particular directly to allow the adhesive to penetrate both sides of the fibers of such paper material. And therefore the fibers of one paper layer are directly bonded to the fibers of another paper layer by an adhesive. The advantage of this is a particularly firm hold, which cannot be achieved in this way if there is a barrier layer of plastic between the paper materials. The combination of features according to the invention thus achieves that the paper material of the kraft paper layers is directly bonded without intermediate layers such as plastic films, so that the adhesive can penetrate into the fiber matrix of the paper material, thereby kraft paper layers to each other A well retained and kraft paper layer of barrier layer is achieved. Interposed plastic layers are believed to weaken the layer structure due to elasticity and / or their flow behavior.

According to the invention according to the invention, shells in cans can be produced in standard winding systems, in which case they are processed into a laminate of barrier film and kraft paper at high speed in a mandrel covered by a rigid barrier layer, which is used previously. This is because it does not tear much more than pure films or laminates.

The present invention takes a different route than is known in the art in which the inner barrier layers are made as thin as possible to overlap so that the maximum deviation in shell thickness is kept low. In the present invention, the disadvantage of its larger thickness difference in the overlapping region of the seam where the thicker inner barrier layer is folded so that a commercially available can having a can shell formed mainly of cardboard or paper material is the first result is A thicker inner barrier layer is intentionally chosen than offset by its advantages in terms of stability and overall layer structure.

The barrier layer preferably has a layer thickness between 0.060 mm and 0.145 mm. The kraft paper layer of the barrier layer preferably has a layer thickness between 0.065 mm and 0.090 mm. The kraft paper layer of the barrier layer preferably has a tensile strength (MD) of at least 4.0 kN / m and a tensile strength (CD) of at least 2 kN / m. Preferably, the diffusion-tight barrier film or diffusion-tight barrier laminate has a layer thickness between 0.033 mm and 0.055 mm.

Preferably, the barrier laminate comprises one aluminum layer and at least two plastic layers, such aluminum layer being between the two plastic layers.

Preferably, the thickness of the shell over the circumference of the can is constant or has at least one deviation, the deviation comprising at least one elevation, wherein the thickness of the shell on the position of the largest height is constant. The thickness is up to 160% of the remainder of the shell, and in absolute terms the largest height is up to 290 μm.

Preferably, at least two additional kraft paper layers wound separately from each other are mounted on the barrier layer.

Preferably, such at least two kraft paper layers have at least one edge region which does not overlap by itself or has a reduced thickness in itself and in the overlap region.

By this feature according to the invention, at least two further kraft paper layers in their respective joint or overlapping areas are themselves achieved without or merely increasing the allowable increase in layer thickness.

Preferably, each layer thickness of at least two of the additional kraft paper layers is in each case selected from a range between 140 μm and 175 μm. The tensile strength of each of the kraft papers in the kraft paper layers is preferably at least 10 kN / m (MD) and at least 5 kN / m (CD).

Preferably, the additional kraft paper layers and / or the additional layers of paper or cardboard material are each wound in the longitudinal direction. Preferably, their joint or overlap regions are located in different peripheral zones, or the joint edges of the two kraft paper layers facing each other are preferably offset from each other.

Preferably, the joint or overlap region of such kraft paper layer adjacent to the barrier layer is offset relative to the folding seam of such barrier layer.

Less preferably, due to the more complex fish, the barrier layer and the adjacent kraft paper layer meet the folding seam of the barrier layer on both sides such that the widened region of the folding seam is accommodated in the gap between the joints of this kraft paper layer. It can be designed to be.

Preferably, the can has an outer seal layer applied externally to the kraft paper layers, which may be present, for example, as a film, laminate or coated paper. Preferably, the barrier layer, preferably at least two further kraft paper layers and preferably also the outer seal layer on the winding system are produced in succession to form a hollow tube from which individual hollow cylinders are cut out.

Alternatively, the outermost of the at least two kraft paper layers may already exist as a laminate of kraft paper layer and barrier film before winding, in which case the barrier film is placed outside of the composite can shell after the winding has taken place.

The outer barrier film or outer seal layer outside the composite can shell may be a semipermeable film that allows moisture to escape from the can shell but does not allow moisture to enter the can shell from the outside.

The material of the outer barrier film or outer seal layer outside the composite can shell may be recyclable or renewable PE, biodegradable PE, EVOH or other known barrier materials.

In an alternative embodiment, the outer seal layer is attached only after cutting of the individual hollow bodies. This can be done by pulling the tubular sheaths of the outer hollow airtight material over the individual hollow bodies and fixing them. Preference is given to a shrink tube formed of a shrink film and drawn over a cylindrical hollow body and formed by heat on the can shell and associated diameter reduction. Preferably, the two cut edges of the hollow body are covered with a tubular sheath so that moisture cannot penetrate. The placement of the shell or shrink tube is advantageously done before the two ends of the individual hollow bodies are formed to the outside. Adhesion or molding of the shell or shrink tube to the hollow body can be carried out before or during the molding of the ends of the hollow body.

After the individual hollow bodies are cut out, the outer sealing layer can also be applied by coating them or by wrapping them with a film, in which case the two cut edges of the hollow bodies are preferably covered with a coating or film.

Applying the outer sealing layer after cutting of the individual hollow bodies is due to the materials used, in particular due to the adhesive and its application amount, that if the outside of the layer structure in the winding system is already sealed the two The layer structure on the cut edges is particularly advantageous in that it will not be sufficiently dry.

Alternatively to the outer barrier layer in the form of a film, the outermost of the at least two kraft paper layers may already be coated on one side with a barrier material, for example paint, later on the outer side before winding.

Less preferably, a barrier material such as paint can be applied to the outside of the hollow tube or to a separate hollow cylinder after production.

For example, an aqueous polymer coating or UV paint may be used as the paint.

Preferably, the cut edges of the individual hollow cylinders to which the paper material of the kraft paper layers are exposed are sealed, for example by applying a tape or film or by coating with a barrier material such as paint, waterproof adhesive or liquid plastic. Particularly preferably, the cut edges are sealed by impregnation, i.e. by applying a liquid that penetrates or somewhat sucks into the fiber matrix of the kraft paper layer at the cut edges to form a liquid resistant edge zone in the kraft paper. Such impregnation may also be used when the outermost layer of the can has one (if overlapping) or two (for butt joint seam) exposed longitudinal absorbing edges.

For impregnation, polymer mixtures of aqueous solutions or aqueous emulsions are preferably used.

Preferably, the cutting edges of the individual hollow cylinders are bent outward to facilitate the placement of the bottom element and the cover, or to improve the retention of the bottom element and the cover on the hollow cylinder.

Through the present invention, it is possible to close the can shell with the standard covers of the aluminum cans, and it is also possible to remove and close the cans during the standard filling of the aluminum cans, in the region of the seam where the can shell is folded without exceeding the required maximum layer thickness. This is because the barrier layer still has an acceptable variation in shell thickness.

Previously, cans made of non-metallic materials decomposable in the industry have major conditions such that the required compressive strength is not at least permanent and certainly not sufficiently achieved. After years of development, however, it is now possible to produce such containers with sufficient compressive strength, which can still be designed for the market and seamlessly integrated into the systems for downstream filling of the cans. .

In the case of fillings of beverages, the cans can be treated with little or no effort to convert to existing plants, so the threshold for product conversion is significantly lower than for composites for pressurized media, especially carbonated beverages. Requires manufacturing, filling and sealing systems.

Because the shell is lower and at least similar in shape, the can is visually and haptically similar to the aluminum can, so consumers are not aware of any differences at first sight or are less suspicious of new types of packaging.

Surprisingly, the hollow cylinder of the container according to the invention is a general packaging made of paper or cardboard material if the winding mandrel is shaped or dimensioned according to the can to be produced so that production costs and mechanical development efforts are low. It has been found that it can be produced in plants used for winding of metals.

Advantageously, for the production of hollow cylinders winding mandrel systems known as the use of a round winding mandrel can be used when the individual layers of the can shell according to the invention are fed transversely around the mandrel, and preferably secured together over the entire surface Thus, standard plants which continue to operate with little adaptation effort for the production of can shells according to the invention can be used. The round structure of the can according to the invention is required so that it can be closed with standard can covers or the cylindrical body is more resistant to pressure than another shape, for example an approximately rectangular body with rounded corners, which is a general packaging It is very common for a purpose.

Advantageously, with the construction of the composite can shell according to the invention, pressure-tight containers, which have previously been used for the packaging of conventional consumer goods, can be produced in the plant. Surprisingly, by using kraft paper layers and barrier layers made of barrier films or barrier laminates in the preferred thickness range of the present invention, it has been shown that the operating speed of known plants can be advantageously increased, which is a barrier film or barrier in the mandrel. Stretching of the laminate is prevented because it turns out to be much stronger with straight winding than with spiral winding.

The folded seam folds the two edges of the barrier layer away from the winding mandrel and welds them together in a film-to-film manner, then folds the welded edges onto one side of the barrier layer and folds them into the barrier layer. It can be produced by bonding to its own kraft paper layer. Alternatively, the folded seams according to the untested variant may also first recoil the barrier layer at one edge and thus the barrier film in the wound mandrel after adhering or attaching the kraft paper layer onto the kraft paper layer. The unopened edge of the barrier layer in the downward facing state could be formed by welding or adhering to the barrier film on the folded back edge.

As a result, both methods achieve a compact folded seam with the same configuration.

At least some displacement of the individual layers known from the prior art has proven to be suitable for not creating any structural weakness that would be present in the overlapping regions in the case of overlapping. Known chamfers or steps at the edges of the layers can advantageously take place in at least two further kraft paper layers of the layer structure according to the invention, so that at least two kraft paper layers are themselves Overlap, but such overlap zones do not lead to an increase in the layer thickness.

Instead of wrapping the at least two other kraft paper layers as well as the barrier layer in the longitudinal direction of the mandrel, such at least two additional kraft paper layers can also be wound obliquely around the straight wound barrier layer, in which case such displacement regions Chamfering or grading of edge regions of the and kraft paper may occur. Oblique winding of at least two additional kraft paper layers may occur for each layer in the same direction or against each other. This variant, however, with additional kraft paper layers wound at an angle, has the disadvantage that the joint areas or overlapping areas of such kraft paper layers intersect the longitudinal seam of the barrier layer, with the result that weak points result in these locations. Has In the case of reverse winding conversely, joint areas or overlapping areas of at least two kraft paper layers may also intersect so that weak spots may also appear as a result there.

Therefore preferably at least two kraft paper layers are also wound.

It has proven advantageous if additional cooling devices for cooling such mandrels are provided in addition to known mandrel winding systems. Such mandrel is preferably provided with an anti-stick surface. The use of lubricants may be omitted by the cooling and / or anti-stick surface, or its use may be at least limited.

On the one hand, in the present invention, the barrier layer is particularly important because it must not be too thick, otherwise the folded seam is too thick, which can lead to creeping leaks in the cover area and the bottom element, which is of particular importance. Since the strength of the kraft paper layers is greatly reduced by contact with moisture, it results in subsequent rupture of the pressurized can. On the other hand, the barrier layer should not be too thin to withstand the tensile forces acting in the region of the folded seam so that there are no creeping leaks. The compressive forces acting on the inner gap of the folded seam are converted into tensile forces acting in the circumferential direction of the can by 180 ° folding of the overlapping zones of the barrier layer, which are due to the areas of the kraft paper layer of the barrier layer directly bonded to each other. Is absorbed.

A less preferred or advantageous possible variant from the present invention is that it uses paper or kraft paper webs laminated with plastic (eg PE) instead of one or both kraft paper layers and joins the layers together. It may be provided in that it is made by adjacent plastic layers of two welded layers. Thus, at least one layer will have an outer PE film and at least one further layer will have an inner PE film, which together when applied on a mandrel, in particular by ultrasonic welding, in a winding machine Are welded. Of course, all the layers can be fixed together by plastic-plastic (PE-PE) welding. Although this alternative embodiment is not claimed in the present application, as it is assumed that it is not advantageous because of the larger layer thickness of the barrier layer and the poorer hold of the layers relative to each other, as the alternative embodiment claimed, Such non-claimed alternative embodiments are also explicitly addressed and disclosed. In order to reach this alternative embodiment, the adhesive is applied in at least one or all parts of the present description, which in theory refers to an adhesive for bonding two surfaces which in each case are otherwise bonded and welded together. It is possible to replace with plastic film. PE-PE welding is common in the manufacture of beverage cartons, which have the disadvantage that they are not suitable for carbonated beverages or mediums having or generating strong static pressure. The layer structure of the beverage carton (barrier layer (PE or PE-Alu-PE) -paper-plastic layer (PE)) winds at least one additional layer over it with an inner plastic layer (PE) and an outer cardboard or paper layer Can theoretically be used as the innermost layer of the can with a longitudinal seam (simple overlap with the inner strip, as is often the case in beverage cartons or folded seams), the outermost layer of such a layer structure being the outer barrier layer. And for example made of PE. However, unlike conventional beverage cartons, the layer structure is cylindrical and will be closed with appropriate closure elements (can bottom and can cover) instead of welding the layer structure to itself at the end. The invention is illustrated based on the figures:

1 is an exploded view of a fluid container according to the present invention, in the form of a beverage can according to the first embodiment;
FIG. 2 is a schematic cross-sectional view of the beverage can from FIG. 1 made of two layers shown in a greatly enlarged view.
3 is a schematic cross-sectional view of a beverage can in accordance with a second three-layer embodiment, in which enlarged layers are shown.
4 is a schematic cross-sectional view of a beverage can having a first layer with a barrier layer therein, overlapping the winding of the two edge zones of the layer, leading outwards, welded with the barrier layers and then applied to the adhesive on the wound layer; The figure which shows that it is applied and adhere | attached by it.
5 schematically illustrates the manufacturing process of cylindrical can shells.
6 schematically illustrates the bend of the edges of the can shell;
7 shows schematically the placement of the closure element.
FIG. 8 illustrates another variant of the contour performed in a diameter section with a silicone based sealing ring. FIG.
FIG. 9 illustrates the finished can in the longitudinal section in the height direction with beaded tight edges on the bottom and cover. FIG.
10 shows schematically a first section of a plant according to the invention for filling cardboard or paper composite can shells and / or aluminum can shells.
11 shows schematically a second section of a plant according to the invention for filling cardboard or paper composite can shells and / or aluminum can shells.
12 shows schematically a third section of a plant according to the invention for filling cardboard or paper composite can shells and / or aluminum can shells.
13 shows a longitudinal section through a particularly preferred embodiment of the cylindrical can shell according to the invention.
14 shows the layer structure in detail of a longitudinal section through a particularly preferred embodiment of a cylindrical can shell according to the invention.
15 shows the layer structure of a cylindrical can shell according to the invention in a detail view of a cross section of a longitudinal folded seam of a barrier layer.
Figure 16 shows a longitudinal section through an alternative embodiment of a cylindrical can shell according to the invention with one barrier layer and two kraft paper layers.
FIG. 17 shows a longitudinal section through an alternative embodiment of a cylindrical can shell according to the invention with one barrier layer and three kraft paper layers.
18 shows a longitudinal section through an alternative embodiment of a cylindrical can shell according to the invention with one barrier layer and four kraft paper layers.
19 shows the layer structure of a cylindrical can shell according to the invention in detail in cross section through a longitudinally folded seam of the barrier layer with sealing strips on the outer seam.
20 schematically illustrates possible overlapping regions of kraft paper layers.
FIG. 21 shows the layer structure of a cylindrical can shell according to the invention in a detail view of a cross section through a longitudinal folded seam of a barrier layer with overlapping seams of an outer barrier layer.
FIG. 22 shows the layer structure of a cylindrical can shell according to the invention in a detail view of a cross section through the longitudinally folded seams of the barrier layer with the folded seams of the outer barrier layer.
FIG. 23 shows the layer structure of a cylindrical can shell according to the invention in a detailed view of a cross section through a longitudinal folded seam of a barrier layer with sealing strips on an outer seam.
FIG. 24 shows the layer structure of a cylindrical can shell according to the invention in a detail view of a cross section through a longitudinally folded seam of a barrier layer with overlapping sealing of the joint seams of the outer barrier layer.
25 shows an extension of a winding plant according to the invention with a device for sealing external longitudinal seams.
FIG. 26 shows an extension of a winding plant according to the invention with a device for introducing an adhesive when folding a fold joint;
FIG. 27 shows the layer structure of a cylindrical can shell according to the invention with a hot melt seal of the butt joint seam of the outer carrier layer. FIG.
FIG. 28 shows an unclaimed layered structure of a cylindrical can shell in a longitudinal section through folded seams.

Before discussing the respective figures, the fluid container according to the present invention should be described in general terms. Fluid containers, in particular fluid containers in their design, such as beverage cans, have hollow cylindrical can bodies, bottom members and cover members designed as pressurized containers and comprising an interior for receiving beverages for this purpose, in this case the bottom The member closes the first longitudinal end of the formed hollow cylindrical can body and the cover member closes the second longitudinal end of the hollow cylindrical can body. The can body comprises at least one wrapped inner material layer and one wrapped outer material layer, ie at least two wraps or layers of cardboard composite or kraft paper, the layers extending exactly 360 ° or in another embodiment. Extends slightly longer than the entire wrap. Combinations of layers with exactly one wrap length and those with slightly more are possible. These layers are wound at right angles to the axis of the can body to be produced to produce maximum compressive strength, and then the necessary overlap is made so that the seams have a minimum length. Spiral windings where the longitudinal edges of the wound bands meet together form tight overlaps but the seams require longer seams. Such windings are also called spiral windings and they are found so far as containers for cylindrical table bombs or stacked crisps or containers for all kinds of other suitable products. The wound inner material layer of the pressure resistant and preferably heat resistant can according to the invention has an inner seam extending in the axial direction and is coated on one side on the side facing the inside of the can with a gas and aroma tight barrier composite or The outer material layer, formed by the kraft paper layer, is formed by the kraft paper layer with outer seams, and such seams formed by overlapping are preferably offset relative to that of the inner material layer with respect to the circumference of the can. In the presence of the third layer of cardboard composite material, its overlaps or seams are preferably staggered with respect to the seams of the central layer again with respect to the circumference of the can.

With such a fluid container, a beverage container or cylindrical beverage can is provided in a structurally simple manner and at cost, which is characterized by its simple structure and the use of reusable materials. Such beverage cans are surprisingly designed and can be made to be sufficiently pressure resistant, especially in several layers and wraps, so that they can be used in carbonated and non-carbonated beverages, mainly made of bare cardboard composites. But can withstand pressures up to 11 bar. Except for a minimal inner coating or barrier layer, the shell consists mainly of cardboard material or kraft paper. This beverage can is safe for food. The can body according to the invention consists of cardboard or even paper, ie kraft paper and no longer consists of aluminum. By sealing the inner material layer with the aid of the barrier composite, a barrier against vapor, aroma, fat and oxygen is created. This barrier composite is applied by a hot casting method, for example by an extruder. The material used for the barrier composite is at least one layer of a polyolefin layer and a binder. If desired, a layer of aluminum may additionally be used, in which case the total surface weight of this innermost layer may be between approximately 60 g / m 2 and 130 g / m 2. In a further alternative, the barrier composite can further comprise a layer of ethylene-vinyl alcohol copolymer, whereby a total surface weight between 50 g / m 2 and 100 g / m 2 can be achieved.

The kraft paper layer of the outer material layer is preferably coated with a polyolefin layer on the side facing away from the inside of the can. This polyolefin layer consists of polyethylene PE or polyethylene terephthalate PET with a gram of at least 10 g / m 2 and at least 50 g / m 2. The ideal gram was found to be 20 g / m 2. In this case, the advantageous barrier effect of polyethylene terephthalate PET can be used. Therefore, these beverages can make an important contribution to protecting the environment and reducing waste.

Given the fact that the beverage can function as a packaging and there is a need to label the contents accordingly, the kraft paper layer of the outer material layer is directed away from the inside of the can, which can be printed or painted in a waterproof manner. It is formed on one side. So you can use an exterior surface to print or paint your advertising message. The wound inner material layer and the wound outer material layer are preferably stuck together over the entire surface. In this way, it is ensured that the joints remain offset relative to the can's circumference and the compressive strength is increased.

In order to increase the stability of the fluid container or beverage can in an environmentally friendly manner, triple wrapping is advantageously produced by at least one wound intermediate material layer applied between the wound inner material layer and the wound outer material layer. It is also formed by a kraft paper layer, such an inner material layer, at least one intermediate material layer and an outer material layer are glued together on opposite kraft paper layers over the entire surface. The at least one wound intermediate material layer has an intermediate joint, which is preferably offset with respect to the inner joint and preferably with respect to the outer joint with respect to the circumference of the winding. The staggered arrangement of the inner joint, the middle joint and the outer joint has proved particularly advantageous in terms of tightness and pressure resistance to filling with carbonated beverages.

Particularly advantageous are barrier composites of the innermost layer of the polyolefin layer and the at least one adhesion promoter layer. To increase the mechanical stability of the inner material layer as far as achieving particularly high compressive strengths for pressures above 11 bar, the barrier composite may further comprise a layer of aluminum and a total gram of at least 60 g / m 2 and up to 130 g / m 2. Can be. By choosing such a material, however, the weight of the fluid container is only slightly increased, while the inner material layer gains toughness through proper material selection.

Alternatively, in order to increase the mechanical stability of the barrier composite in place of a single layer of aluminum, an ethylene-vinyl alcohol copolymer layer can be further used, in which case the total grams are at least 50 g / m 2 and up to 100 g / m 2. Ethylene-vinyl alcohol copolymers also have the necessary properties to form barriers. In a further alternative embodiment with increased mechanical stability, one layer of polyvinyl alcohol having a total gram of at least 50 g / m 2 and up to 100 g / m 2 may be used as the barrier composite. In this case, polyvinyl alcohol has high tensile strength and flexibility.

Kraft paper layers having a gram of 60 g / m 2 or more and 180 g / m 2 or less are suitable in that the total weight of the fluid container is low. The bottom element and / or cover element can be manufactured for good pressure resistance of a metal can as is conventionally preferably made of aluminum.

In the following, the individual figures are described and described in detail. In figure 1 a fluid container according to the invention in the form of a beverage can 1 is shown as a schematic single part illustration. The beverage can 1 may comprise a hollow cylindrical can body 2, a bottom element 4 and a cover element 5, in which the pipe section or can interior 3 serves to receive the beverage. The bottom element 4 serves to close the first longitudinal end 6 of the can body 2, and the cover element 5 serves to close the second longitudinal end 7 of the can body 2. do. The bottom element 4 and the cover element 5 are preferably made of metal, preferably aluminum. The beverage can 1 may have a diameter of 35 mm to 600 mm and a height of 100 mm to 250 mm, preferably a height of 100 mm or more and a diameter of 45 mm to 70 mm.

FIG. 2 shows a first variant with a can body of two layers in cross section, the layers being shown in large scale in principle. The first kraft paper layer 18 having an in-line polyolefin layer as the barrier composite is wound around the inner layer 11 around the central cylindrical steel mandrel, and the edges in the direction wound around the first seam 15 are bonded. Or welded. Then the edges lying in the winding direction on the seam 16 on the side of the can body 2 opposite the seam 15 are welded or glued so that a can body 2 with a hollow can interior 3 is produced. As a result, the second kraft paper layer 18 is wound on the first layer 11 as an outer material layer 12.

In FIG. 3 this second embodiment of the first embodiment of FIG. 2 in that the structure of the can body 2 in this second embodiment has three layers 11, 14, 12 of material instead of only two layers. A second embodiment of the beverage container 1 is shown in cross section through the can body 2 so that the embodiments are different. The following description applies to both embodiments, in which the differences are addressed between the differences between the two embodiments.

In both embodiments illustrated in FIGS. 2 and 3, the can body 2 comprises a wound inner material layer 11 and a wound outer material layer 12. In the second embodiment according to FIG. 3 there is an additional layer of material, ie there is a wound intermediate material layer 14 disposed between the inner material layer 11 and the outer material layer 12. Two or more intermediate material layers 14 may be arranged between the inner material layer 11 and the outer material layer 12, in which case the three intermediate material layers 14 represent the maximum kind, and No further increase in the number was found to be necessary to increase the stability.

In the inner material layer 11, the outer material layer 12 and in the second embodiment, the intermediate material layer 14 is released from the material web rolls. Then, preferably in the machine their edge regions form a slope or step so that later overlapping edge regions are polished so that they are not thicker than the thickness of the cardboard composite layer itself. Thereafter, for the production of the can body 2 and the subsequent closed can 1, the material webs are wound at right angles to the can body 2 around the mandrel 23 laterally in their course direction. The next overlapping edge regions of the individual material layers are connected to each other in a form-fitting manner by adhesion. As a result, the wound inner material layer 11 has an inner joint 15 and the outer material layer 12 has an outer joint 16. Thus, in the second embodiment, the intermediate material layer 14 has an intermediate joint 17.

For the function and aesthetics of the fluid container, in particular also the beverage can, the individual seams 15, 16 and optionally 17 are not arranged on the same circumferential positions as shown in FIG. In the first embodiment and in the second embodiment of FIG. 3, the inner joint 15, the outer joint 16, and the middle joint 17 are bonded together with material layers 11, 12, and optionally 14. Then at different circumferential positions. The inner joint 15 is arranged offset by 180 ° relative to the outer joint 16 as shown in FIG. 2 or the joints 15, 16, 17 are only approximately 15 ° as shown in FIG. 3. It doesn't matter that much. The joints 15, 16, and optionally 17 are advantageously offset relative to one another and not located at the same circumferential position of the can body 2.

As a base material, the inner material layer 11 and the outer material layer 12 are each formed by a kraft paper layer 18, where-if present-the intermediate material layer 14 is a kraft paper layer ( 18). At this time, each kraft paper layer 18 preferably has a gram of at least 40 g / m 2 or more and 180 g / m 2 or less, preferably 80 g / m 2 or more and 120 g / m 2 or less. As alternative substrates, color paper with high tensile strength is also considered.

In both embodiments, according to FIGS. 2 and 3, the kraft paper layer 18 of the outer material layer 12 is coated on one side on the outer face facing away from inside the can with the polyolefin layer 19 as a barrier composite. . The two-layer structure of this outer material layer 12 is schematically indicated by dashed lines, where the representations of FIGS. 2 and 3 do not reflect the actual layer thickness. The polyolefin layer 19 preferably has a gram of 10 g / m 2 or more and 40 g / m 2 or less, in which case a gram of 20 g / m 2 is preferable. In addition, the polyolefin layer 19 may be provided with or without semipermeable properties. As an alternative to the polyolefin layer 19 (not shown), the kraft paper layer 18 of the outer material layer 12 may be printed or painted on one side on the outer surface facing away from the can interior 3.

Furthermore, in both embodiments according to FIGS. 2 and 3, the inner material layer 11 has a gas-tight and aroma tight barrier composite 20 on either side facing the can interior 3. Coating. In other words, the two-layer structure is schematically indicated by broken lines in the respective figures. The barrier composite 20 itself is preferably multilayer in turn and comprises at least one layer of a polyolefin layer and a binder. In addition, the barrier composite 20 may have an aluminum, ethylene-vinyl alcohol copolymer or polyvinyl alcohol layer. In the case of an additional layer of aluminum, the barrier composite 20 preferably has a total gram of at least 60 g / m 2 and not more than 130 g / m 2, and preferably has a total gram of 110 g / m 2. In the case of an additional layer of ethylene vinyl alcohol copolymer or polyvinyl alcohol instead of aluminum, the barrier composite 20 preferably has a total gram of 50 g / m 2 or more and 100 g / m 2 or less, preferably 70 g / m 2. In view of the layer structure, in the first embodiment according to FIG. 2, the wound inner material layer 11 and the wound outer material layer 12 span the entire surface on opposite surfaces of the respective kraft paper layers 18. It can be seen that it adheres. In the second embodiment according to FIG. 3, the inner material layer 11, the intermediate material layer 14 and the outer material layer 12 on opposite kraft paper layers 18 are glued together to their entire surface. .

In summary, this exemplary fluid container described as a beverage can is mainly made of cardboard material and is suitable for both non-carbonated and carbonated beverages. It is preferably a three-piece, linearly manufactured, cylindrical fluid such as the shape of a 5 liter beer keg, mainly for uniform pressure absorption, although other forms are theoretically possible. Courage. The fluid container is each made of a can body 2 made of a multilayer cardboard and barrier carton composite, preferably a bottom element 4 made of metal, preferably aluminum, and preferably made of metal, also preferably aluminum Cover element 5. The cover element 5 further comprises a device known for the opening, preferably a pull-ring, in which case a means can be provided which allows to selectively close it again.

For production, the innermost winding 11, ie the innermost layer 11 which acts as a barrier web, is formed around the mandrel 23 as shown in FIGS. 4 and 5. In this case, the edge regions of the layer which protrude beyond the circumference of the winding are preferably folded outward, so that the inner barrier layers, for example PE, are next to each other. These barrier layers of the two edge regions are then welded together via induction or ultrasonic welding. Thereafter, the two welded edge regions are pivoted together on one side of the layers. Therefore, the edge area on the right side of the image is flipped 180 °. Its kraft paper surface meets the kraft paper surface of the wound layer and the channel 52 formed during the pivoting is provided with an adhesive 22 so that the two together welded edge regions are tightly bonded and sealed to the wound layer. The web thus does not have a joint-to-joint measure for this adhesion but intentionally produces a three layer overlap of about 8 mm wide. Since the channel 52 is filled with the adhesive 22, transport of liquid is effectively avoided during the subsequent filling process.

The next layer 14 of cardboard composite material is slightly offset simultaneously and spatially as shown in FIG. 5 around the existing layer 11 and the mandrel 23 connected thereto according to the version of FIG. 4, and then Layer 14 is connected with the bonding. The edge regions of the second layer 14 are preferably grounded stepwise so that they can be positively connected to each other by the overlap 45, and this overlap 45 is glued to form the central seam 17. do. In FIG. 5 the third layer 12 of the cardboard composite, ie the outer layer, can also be very slightly offset locally and around it, and then the central layer 14 can be wound and the positive overlap also the outer seam. It can be glued to form (16). The outermost layer can be coated with an outer material, for example a layer with very fine pores, allowing water vapor to escape from the can body, while conversely, it is impossible to penetrate water into the can. Such coatings are preferably polyethylene PE, polypropylene PP or polyethylene terephthalate PET. The outermost seam 16 can be sealed with a sealing strip (shown in dashed lines) made of PE, PP, PET, with or without bonding agent or adhesive, depending on its shape with or without heat. Apply. Instead of securing the strip 46 to the resulting continuous tube 27 as a result of moving it on the mandrel 23, the seam 16 of the outermost layer can be hot and thus sealed by liquid PE.

For industrial production of cans made of cardboard composite material, this material is supplied in the form of its respective coating in rolls and prefabricated sheets of kraft paper, the material being rolled from them and wound as illustrated in FIG. 5. Supplied to the device. In the example of FIG. 5, for example, three rollers will be present as webs for the three layers 11, 14 and 12 to be wound. After unrolling, the edge regions of the webs 14, 12 are preferably grounded by the machine in order to create a sloped surface 44 or step 21. Primarily these rollers can be supplied to the can filler for the production of fluid containers together with adhesive and bottom elements and cover elements, but there are no empty and thus no more bulky products.

Before being fed to the winding device, the webs 11, 14, 12 are coated on one of its flat sides with an adhesive, preferably glue.

Then, as shown in FIG. 5, the "continuous" webs of the individual layers 11, 14, 12, ie the ones that form the innermost layer 11 first, are placed along the cylindrical steel mandrel 23 fixed. It is fed and pulled and wound by a machine station around the steel mandrel 23. The material webs run between the steel mandrel 23 and a plurality of continuous rollers (not shown) each having a U-shaped cross section. Using the innermost layer 11, welding of outwardly protruding edges takes place in its barrier layer as shown in FIG. 4. The innermost layer 11 is then wound into a tube advancing over additional sections of the steel mandrel 23. Contact rollers (not shown) hold the innermost layer 11 supplied on the mandrel 23, and the welded seams produced by induction or ultrasonic waves are folded and pressed to the cardboard composite material of the innermost layer 11. Are bonded to the outside. The finished innermost layer 11 is then conveyed to the mandrel 23.

Next, the central layer 14 is applied locally to the innermost wrapping or layer 11 on the same machine immediately behind the innermost layer 11. The inclined surface 44 is preferably cut into steps 21 or longitudinal edges of this central layer 14, overlapped by the winding of the mandrel 23 and bonded by a previously applied adhesive. And finally, the outer layer is also applied at the same time and slightly reset locally to the previously wound layer 14.

A pipe 27 made of a cardboard composite of three bonded layers, shown in FIG. 5, delivers the guillotine to the cutting device 26 clocked back and forth, for example, as shown in FIG. 5. The pipes 27 are cut into pipe sections 28 at locations. Such cutting may preferably be carried out with a known multi-rotating blade machine as well as a movable guillotine. In this case, a carriage with several rotary blades has a continuous tube 27 that moves at production speed and thus can cut several pipe sections 28 in one operation. After cutting, the can sections 28 are preferably passed through a heat tunnel to remove glue moisture. Heat can be generated in a variety of ways. Preference is given to hot air.

After cutting the pipe sections 28 to the desired length, according to the desired can volume, the cutting edges of the open ends of the pipe sections 28 are formed into projections by the machine. For this purpose rotary spreading tools are inserted into open ends from both sides. 6 shows the probability for this spread. The can body 2 is inserted into a hollow cylinder 48 with rounded inner edges 51. Using a steel roller 49 that rotates about an axis 50 retracts this curved inner edge 51, in which case the axis 50 is moved to define a cone wall. The steel roller 49 allows one or more upper edge portions of the can body 2 to pass over the curved edge 51 and to slightly unfold the layers. The result is a projection, as shown in FIG. 7 below. The cut edges are preferably sealed after such carding or the diffusion is carried out by painting with a dispersing adhesive such as liquid polyethylene PE or a dispersing adhesive or other suitable fast-setting and food grade adhesive, for example. Moisture cannot penetrate the inside of the kraft paper layer, since subsequent filling inevitably occurs in a humid atmosphere. The cutting edges are then heat treated once again to minimize setup time. In this respect, infrared is preferred for this. These tube sections 28 are then placed in a continuous upright position in the transport device and then pass through a carousel 30 as shown in FIG. 10, thus providing a machine 32. At the open top of each pipe section 28 around the edge region of the open pipe section 28 in a manner that initiates and tightly seals an isolated closure element, such as for example the bottom element 4, from the supply magazine 31. Forming an outer edge region of the bottom edge radially outward of the closure element in the radial direction.

7 illustrates the process of firmly pressing the closing element in the form of a bottom element 4 or a cover element 5. The bottom element and cover element can be standard floors or standard covers that can be used to seal existing aluminum cans and then assembled into the same machine. The bottom element 4 or cover element 5 is made of aluminum and has a radially projecting edge area 41, ie an area protruding beyond the diameter of the can body 2. The bottom element 4 or cover element 5 with the edge region 41 overlaps the edge region 42 of the can body 22 by a machine. The pressing is then carried out by the machine 32, for which it is pressed together with the cantilevered two layer sections 41, 42, ie the edge 41 and the edge 42 of the can body, That is to say, by rolling at about 360 ° or more, a tightly formed joint is produced. As shown in FIG. 7, the cut edge of the can body 2 is a seal 37 made of a moisture-tight material. The cover element 5 or bottom element 4 generally has a composite material 38 which is an elastic sealing material applied in the region of the protruding edge region 41 facing the edge region 42 of the can body 2. .

Preferably, the composite material 38 extends from the interior of the curl 39 of the cover element 5 or the bottom element 4 to the shoulder 40 of the cover element 40, The composite material 38 extends at least partially above the height of the shoulder 40 and at least partially exceeds the inner radius of the curl 39. Preferably, this composite material 38 extends over at least half of the height of the shoulder 40.

8 shows an alternative bottom or cover 4, which is shown here in the opposite section. As can be seen, the silicon-based sealing ring 47 is inserted in the downward open channels formed by it. The cover is then installed on the same machines as in a conventional aluminum can. The silicone seal provides additional adequate density and the overlapping areas are rolled together inward.

10 shows a rotating conveying machine 32 with a carousel 30, which mounts the bottom elements on the can bodies and compresses the edges of the bottom elements to the edges of the can bodies as described above. The pipe sections 28, which are only open on one side, are then inverted in the conveyor channel, with their open side facing up as shown in FIG. It then passes through a carousel filling station 33 that fills each pipe section 28 with a defined fill amount. Finally, as shown in FIG. 12, filled tube sections 28, which are closed at the bottom, pass through the carousel 34, and the machine 35 pulls from the supply magazine 36 above such carousel 34. A singular cover element 5 with a closure is inserted above the open top of each filled tube section, and the edge of the cover element 5 projecting radially in a radial direction is opened around the edge area of the open pipe section 28. Pressed in a sealed manner.

The filled and sealed container 1 appears later as shown in FIG. 9, in which case it is shown in cross section along its longitudinal axis. Above and below the can body 2 and the flanges 43 can be seen that the cover 5 and the bottom 4 are fixed in a sealed manner.

In FIG. 13, a particularly preferred can shell 101 is shown in the longitudinal section through a cylindrical container. The can shell 101 is, from interior to exterior, a barrier layer 102, an inner kraft paper layer 103, a central kraft paper layer 104, an outer paper or kraft paper layer 105 and an outer barrier layer. Has 106.

The barrier layer 102 has, at one point in the circumference, a folded seam that runs in the longitudinal direction of the can shell 101, in which three layers of the barrier layer 102 overlie the others. You lose.

In the region of the folded seam, the can shell 101 has a maximum thickness D max, which is greater than the remaining thickness D of the can shell 101, ie twice the thickness of the barrier layer 102. Therefore, the thickness difference ΔD is twice the thickness of the barrier layer 102.

The difference in thickness rarely plays a role in conventional packaging, but for pressure resistant candles it can remain tight in the area of the cover, or over time the area of thickness difference, ie between the cover and the barrier layer 102. It is very important whether it can penetrate the kraft paper layer in the region of the folded seam. Attempts have been made in the prior art to make the barrier layer 102 as thin as possible, or to hide its folded seams with the intermediate layer. Hiding the folded seam is procedurally complex and can lead to weak points because there is a large gap between the two edges of the middle layer on which the folded seam is laid. According to the prior art, the barrier layer 102 can also be designed as a film, usually plastic aluminum or composite film as thin as possible, with the disadvantages of being simpler or slower and of lower strength or subject to creeping deformation. Can be.

Notwithstanding the prior art, the present invention allows the barrier to be designed as a composite of kraft paper layer 107 and barrier film 107 or as a composite of kraft paper layer 107 and barrier laminate 108 of multiple film layers. For layer 102. This inevitably leads to an essentially disadvantageous increase in the thickness difference in the region of the folded seam, but has the advantage that the barrier layer 102 can be wound better and the folded seam can be more stable.

Preferably, the overlapping length of the circumferentially folded seam of the can shell 101 is between 1 mm and 6 mm, particularly preferably between 2 mm and 4 mm, in particular 3 mm.

14 and 15, a particularly preferred can shell 101 is shown in detail, where the barrier layer 102 is shown as a composite according to the invention of the kraft paper layer 107 and the barrier laminate 108. Barrier layer 102 according to the present invention is a non-type bonding of paper material and plastic, for example, generally requires more specific adhesive and / or more time and paper or paper on paper It is particularly advantageous in that no foreign matter is bonded together in the manufacturing process of the folded seam because it leads to weaker bonding than bonding the plastic to it.

As shown in FIGS. 14 and 15, the innermost layer of can shell 101 is formed by barrier laminate 108 laminated to kraft paper layer 107. Bonding of the barrier laminate 108 and the kraft paper layer 107 occurs before winding the cylindrical can shell 101 already (101). The material of the barrier layer 102 is preferably made in the form of a composite of the kraft paper layer 107 and the barrier laminate 108, which is then wound into a roll and then provided as a roll for the winding process of the cylindrical can shell 101. do.

In the region of the folded seam, barrier layer 102 has a triple overlap with itself. In the area of the folded seam, the barrier laminates 108 are visible from the inside out, and then already tightly bonded to each other before the kraft paper layer 107 is wound. The kraft paper layers 107 are adjoined by further kraft paper layers 107, where they are preferably attached to each other just before winding or during winding, in particular by gluing. The additional kraft paper layer 107 is followed by a barrier laminate 108, which is already firmly connected to each other before winding. The barrier laminate 108 is followed by another layer of the barrier laminate 108, in which case the two layers of the barrier laminate 108 are connected to one another during the winding process, preferably by welding. An additional layer of barrier laminate 108 is again followed by kraft paper layer 107, which forms the outermost layer of the folded seam. The outer layer of barrier layer 102 is formed over the entire perimeter by kraft paper layer 107. The kraft paper layer 107 is not processed, i.e. painted or laminated, on the outside such that the outside is formed by kraft paper material.

The inner kraft paper layer 103 is disposed around the outside of the barrier layer 102 during the winding process, where it is not treated, that is, uncoated or laminated on the inside and outside. The inner face of the inner kraft paper layer 103 is bonded over its entire surface with the outside of the barrier layer 102, where the kraft paper material is bonded directly to the kraft paper material so that the adhesive is bonded to both layers of the fiber matrix Can be penetrated, thereby achieving a particularly high final strength of the adhesive bond.

Less preferably, other adhesives may also be used, such as hotmelt adhesives or two component adhesives, where the lower final strength of the hot melts and the difficulty of treating the two component adhesives are due to the use of glue or water based adhesives. Can be cited as significant drawbacks. Glues herein are understood to be aqueous solutions of adhesive. In particular, known paper glues can be used.

Less preferably, a combination of two or more different adhesives may be used, which may be used together to join the two layers, or may each be used to join the different layers. For example, hotmelt and aqueous adhesives can be applied side by side on the layers to bond the two layers together.

As shown in FIG. 16, at least one additional kraft paper layer 104 is disposed around the outside of the inner kraft paper layer 103 during the winding process and is thus untreated, ie uncoated or laminated inside. It doesn't work.

The use of at least two kraft paper layers 103, 104 is more complicated and associated with higher material costs than using thicker kraft paper layers for can shells; However, it is advantageous to be able to process faster on two thin kraft paper winding machines and that the stability of the can body can be surprisingly increased compared to using one thicker layer.

Preferably, two kraft paper layers 103, 104 and an additional paper or kraft paper layer 105 are used as shown in FIGS. 13 to 15, with an inner kraft paper layer 103 and each central kraft paper layer. 104 is not coated on both sides and outer paper or the kraft paper layer 105 is preferably untreated or coated at least internally.

Particularly preferred can shells are produced having a height in the range 130 mm to 150 mm, an outer diameter in the range 50 mm to 60 mm and an inner diameter in the range 48.6 mm to 58.6 mm.

Particularly preferred sealed cans have dimensions: an outer height of 134 mm, an inner height of 133 mm, an outer diameter of 52.4 mm, an inner diameter of 51.2 mm, an inner volume of about 270 ml to 275 ml, a filling volume of 250 ml.

As described, the can has a barrier layer 102 as the innermost layer, formed from film material and kraft paper. The film material is preferably a composite film comprising aluminum foil and at least one plastic film, which together form a barrier laminate 108. The barrier laminate 108 preferably has an aluminum foil, particularly preferably a layer thickness of 6 μm to 9 μm, which is present between the two plastic layers so that the barrier layer 102 is plastic from the inside out. Layer, aluminum layer, plastic layer, has the structure of kraft paper,

The barrier laminate 108 preferably has the structure of a plastic film, from inside to outside, preferably an adhesion promoter, preferably PE in the form of PE, aluminum foil, preferably Surlyn. It has a structure of film. The individual layers of the barrier laminate 108 particularly preferably have a thickness as follows: plastic film 10 μm to 25 μm, binder 2 μm to 5 μm, aluminum foil 6.5 μm to 7.5 μm, plastic film 10 μm to 25 Μm.

The barrier laminate 108 preferably has a thickness of 30 μm to 55 μm. The barrier laminate 108 has a particularly preferred thickness of 35 μm to 50 μm, in particular 40 μm to 45 μm. Preferably, barrier laminate 108 has a gram of 45 g / m 2 to 75 g / m 2, in particular 50 g / m 2 to 65 g / m 2.

The kraft paper layer 107 of the barrier layer 102 preferably has a thickness of 60 μm to 90 μm. The kraft paper layer 107 of the barrier layer 102 particularly preferably has a thickness of 70 μm to 85 μm. The kraft paper layer 107 of the barrier layer 102 preferably has a gram of 40 g / m 2 to 80 g / m 2, in particular 50 g / m 2 to 70 g / m 2, in particular 60 g / m 2.

The barrier layer 102 applies a preferred layer thickness of 90 μm to 145 μm. The barrier layer 102 has a particularly preferred layer thickness of 110 μm to 135 μm.

The tensile strength MD of the kraft paper of the kraft paper layer 107 is preferably at least 4 kN / m, in particular at least 5.0 kN / m. The tensile strength CD of the kraft paper of the kraft paper layer 107 is preferably at least 2 kN / m, preferably at least 2.5 kN / m.

In a second embodiment of the barrier layer 102, it has the structure of a barrier laminate 108 with layers, from inside to outside, ie a plastic layer, preferably PET in the form of a heat-sealing paint; An aluminum layer in the form of aluminum foil; It has a structure of a plastic layer in the form of an adhesive and a kraft paper layer 107 made of kraft paper. The kraft paper of the kraft paper layer 107 preferably has a gram of 40 g / m². The heat seal lacquer preferably has a gram of 1.6 g / m², an aluminum foil, a layer thickness of 7.7 μm, a gram of 20.8 g / m², and a plastic layer of adhesive, gram of 2 g / m². Overall, this barrier layer 102 has a layer thickness of about 60 μm and a gram of about 65 g / m 2.

Barrier layer 102 is a longitudinal mandrel to form a folded seam to form a tubular body with the inner plastic film of barrier laminate 108 facing the mandrel 107 and the kraft paper layer 107 away from the mandrel. Wind around

The next layer, i.e., the inner kraft paper layer 103, particularly preferably has a gram of 125 g / m < 2 >, a tensile strength MD of greater than 12 kN / m and a thickness of 0.160 mu m. Kraft paper is not processed on both sides. Preferably, the inner kraft paper layer 103 has a gram between 95 g / m² and 135 g / m² and / or a tensile strength greater than 10 kN / m and / or a thickness between 0.140 mm and 0.175 mm.

The kraft paper layer is bonded directly and completely to the kraft paper layer 107 of the barrier layer 102, in particular being glued around the tubular body of the barrier layer 102.

For adhesion, the glue, preferably polyvinyl acetate, preferably is an outer or inner kraft paper layer of the barrier layer 102 in an amount of 10 g / m² to 25 g / m², in particular 15 g / m² to 20 g / m². It is preferably applied to the interior of 103.

The next layer is a central kraft paper layer 104 having a gram of 125 g / m², a tensile strength greater than 12 kN / m and a thickness of 0.160 mm, for example. Kraft paper is not processed on both sides. Preferably, the central kraft paper layer 104 has a gram between 95 g / m² and 125 g / m² and / or a tensile strength MD of greater than 10 kN / m and / or a thickness of 0.140 mm to 0.175 mm.

This central kraft paper layer 104 is bonded directly and in its entirety to the base inner kraft paper layer 103, in particular wrapping it around the tubular body of the barrier layer 102 and the inner kraft paper layer 103. Is bonded.

For adhesion, the glue, preferably polyvinyl acetate, is preferably at the outer or center of the inner kraft paper layer 103 in an amount of 10 g / m² to 25 g / m², in particular in an amount of 15 g / m² to 20 g / m². It is applied inside the kraft paper layer 104.

The can shell 101 formed by these three layers shown in FIG. 16 preferably has a thickness D of 378 μm to 495 μm, in particular 430 μm to 460 μm. The thickness difference ΔD is preferably between 196 μm and 290 μm, preferably between 220 μm and 270 μm. In the region of the folded seam, the can body preferably has a thickness Dmax between 650 μm and 730 μm, where D max is about 150% of the thickness D of the adjacent can shell 101.

Preferably, the can body has a fourth layer formed from the outer paper or kraft paper layer 105. The outer paper or kraft paper layer 105 preferably has a gram of 80 g / m² to 130 g / m², in particular 100 g / m² to 120 g / m². The outer paper or kraft paper layer 105 preferably has a thickness of 70 μm to 120 μm, in particular 90 μm to 110 μm.

The outer paper or kraft paper layer 105 is applied to the winding installation on the central kraft paper layer 104, preferably a glue having an amount of 10 g / m² to 25 g / m², in particular 15 g / m² to 20 g / m², Preferably polyvinyl acetate, preferably attached to the entire surface.

A can shell 101 consisting of a barrier layer 102, an inner kraft paper layer 103, a central kraft paper layer 104, and an outer or kraft paper layer 105 (without the barrier layer 106) is shown in FIG. 17. Illustrated in The thickness D of the can shell is about 550 μm, where the maximum thickness D max in the region of the folded seam is 800 μm, corresponding to about 145% of the thickness D of the adjacent can shell 101. The thickness difference ΔD is about 250 μm. The can shell 101 consisting of the barrier layer 102, the inner kraft paper layer 103, the central kraft paper layer 104 and the outer or kraft paper layer 105 is preferably 500 μm to 650 μm, more preferably. Preferably from 550 μm to 620 μm. The can shell 101 consisting of the barrier layer 102, the inner kraft paper layer 103, the central kraft paper layer 104 and the outer or kraft paper layer 105 is preferably greater than 300 N / 15 mm, in particular 350 N / It has a tensile strength CD of greater than 15 mm, ie greater than 20 kN / m, in particular greater than 23 kN / m. Preferably, the can shell 101 consisting of the barrier layer 102, the inner kraft paper layer 103, the central kraft paper layer 104 and the outer or kraft paper layer 105 is at least 400 g / m 2, in particular at least 450 g / It has a gram that is m².

Preferably, this outer kraft paper layer 105 is preferably on the outside facing side of the can, for example with a single layer barrier film, with or without pinholes, preferably 15 g / m². Gram and / or 15 microns thick or with varnish coated polyethylene (PE).

Alternatively, the outer layer may consist only of the outer barrier layer 106 in the form of a barrier film, with or without pinholes, preferably 25 g / m 2 PE. At this time, the inner kraft paper layer 103 and the second kraft paper layer 104 may be adjusted to their material thickness such that the overall material thickness of the can shell is maintained.

Depending on the height and diameter of the can, it is envisioned that the number of central kraft paper layers 104 may be greater than one, for example, for a can having a height of 245 mm and a diameter of 175 mm, illustrated in FIG. 18. As is preferred the number of two central layers. For example, the preferred thickness per kraft paper layers 103, 104, 105 is 0.160 μm, the thickness of the barrier layer 102 is 127 μm, and the total thickness D is 767 μm.

Depending on the height and diameter of the can, it can be provided that the inner kraft paper layer 103, the central kraft paper layer 104 and the outer kraft paper layer 105 have greater strength, for example H and 245 mm. For cans with a D of 175 mm, each can be 265 µm thick. For example, when the thickness of the barrier layer 102 is 127 μm, the total thickness D is 922 μm.

Increasing the number of layers is advantageous compared to increasing the thickness of the layer, since higher processing speed and higher stability of the can body can be achieved with thinner layers with respect to the whole gram of kraft paper used. .

The tensile strength index MD is a quotient of the tensile strength MD and the grams of the kraft paper used for the kraft paper layer 107 and the kraft paper layers 103, 104, and 105, and preferably in the range of 70 Nm / g to 120 Nm / g. have.

The tensile strength index CD is the quotient of the tensile strength CD and the gram of kraft paper used for the kraft paper layer 107 and the kraft paper layers 103, 104 and 105, and preferably in the range of 35 Nm / g to 70 Nm / g. have.

The tensile strength index MD of the kraft papers used is preferably greater than 80 Nm / g. The tensile strength index MD is particularly preferably greater than 100 Nm / g.

The tensile strength index CD of the kraft papers used is particularly preferably greater than 40 Nm / g. The tensile strength index CD is particularly preferably greater than 50 Nm / g.

In addition to the kraft paper layer 107, the layer structure preferably includes at least two additional kraft paper layers 103, 104 having a specified tensile strength index MD and CD. At least one of the kraft paper layer 107 or additional kraft paper layers 103, 104 may also be formed from other cardboard material having specified tensile strength indices MD and CD. Kraft paper is distinguished from conventional papers by larger tensile strength indices (MD) and in particular CD (cross direction).

Preferably, the kraft paper of the kraft paper layer 107 and the kraft paper layers 103, 104 is not bleached. The paper or kraft paper of the outer paper or kraft paper layer 105 may be bleached, which may be advantageous for printing with a design that is external to it. The outer paper or kraft paper layer 105 may already be printed in the product design before being wound, and such printing may advantageously exist between the paper or kraft paper layer 105 and the outer barrier layer 106. In the cutting device 26, cutting is registered for printing.

19 shows a cross section through a particularly preferred configuration of the can shell 101 according to the invention. In this configuration, the inner kraft paper layer 103 and the intermediate kraft paper layer 104 have side edges of an oblique shape such that the two edges of the layers opposite the respective web material overlap each other, but otherwise the overlapping area There is no substantial increase in the layer thickness of the layer. As shown in FIG. 20, other shapes of edges, such as stepped edges or interlocking edges, are also suitable as an alternative to the oblique shape. Generally speaking, it is desirable for at least one of the two edges of at least one of the kraft paper layers 103, 104, 105 to provide a shape that induces a reduction in the thickness of the overlapping area of the two edges. Particularly preferably, both edges of at least one of the kraft paper layers 103, 104, 105 are shaped such that the thickness of the overlapping edges is equal to the thickness of the layer itself. Particularly preferably, the innermost kraft paper layer 103 has this structure. Preferably, at least one existing central kraft paper layer 104 has such a structure, particularly preferably all existing central kraft paper layers 104.

As shown in FIG. 19, the edges of the outer kraft paper layers 105 preferably meet at the joint, with the gap applying a strip 109 (also referred to as a stream) of PE, PET or PP to the joint area. Or a sealing material is applied by the spray head after forming the can body. Adjacent edges of the outer kraft paper layer 105 are advantageous, as a result of which the gap is more regular and thus visually attractive and less sensitive to mechanical influences from the outside. This is because there is no reduction in the layer thickness of the edge region.

Less preferably, it is assumed that the edges of the inner kraft paper layer 103 and / or the edges of the intermediate kraft paper layer 104 may meet at the joint, which may adversely affect the stability of the layer structure.

In order to manufacture the can shell 101 according to the invention, the barrier layer 102 is first supplied as web material in the longitudinal direction of the mandrel of the winding machine and further travels in the longitudinal direction of the mandrel. Two edges are formed around the mandrel so that these edges meet on opposite sides of the mandrel and the mandrel is now surrounded by the web material.

In order to create the folded seam, the two edges of the web material of the barrier layer 102 are preferably welded to the barrier laminate 108 adjacent to each other. For this purpose the two edges are bent from the mandrel, placed on top of each other and welded. After welding, the two welded edges are pulled to one side such that the edges welded together stop with their kraft paper layers 107 on the kraft paper layer 107 of the portion of the barrier layer 102 surrounding the mandrel. Inverted, at least one of the kraft paper layers 107 may already be provided with a glue to securely bond the two kraft paper layers 107. However, preferably, the barrier layer 102, ie the kraft paper layer 107, is not provided with glue outside thereof.

Therefore, particularly preferably, the winding machine according to the invention is provided as an improvement of the known prior art, for example using an applicator such as nozzle 111, which is the area of the seam where the adhesive (eg glue or hotmelt) is folded. In a targeted manner to at least one of the two juxtaposed regions of kraft paper layer 107. This is shown in FIG. Preferably, the adhesive is intentionally introduced into the free space 110, which may occur or occur due to the stiffness of the kraft paper when the mutually welded edges in the edge region of the kraft paper layer 107 fold to 180 °. That is, when the overlap is applied to the barrier layer 102, a fold or at least close to the fold of the overlap projecting outward of the barrier layer 102 so that the adhesive spreads between the overlap and the underlying cylindrical barrier layer 102. The adhesive is preferably applied to.

This advantageously prevents air trapping in this free space 110, which may adversely affect the stability of the can shell 101. The introduced material, preferably glue 22, holds the kraft paper layer 107 in an area of flexion of 180 ° such that the pressure generated in the can does not lead to tearing of the fibers of the kraft paper layer 107 at the position of flexion. Support in a hardened state. In addition, the internal pressure of the can will pressurize the trapped air in the layered structure, causing the pressure of the trapped air to press against the layered structure from within or the trapped air will escape and attempt to the ends closed by covers. This can cause damage slowly there.

Alternatively, the folding also folds the edge of the web of barrier layer 102 back 180 °, and then folds back-edge kraft paper layer 107 to the kraft paper layer 107 below it. By bonding. In this case, an application device such as, for example, a nozzle is also preferably provided, which is particularly at least in the back-fold area and in particular of the adjacent areas of the kraft paper layers 107 into the free space 110. Adhesive is introduced into one, which occurs while folding the kraft paper layer 107 by 180 ° due to the rigidity of the kraft paper. Folding back and gluing preferably takes place directly in front of the winding machine during the supply of the web material. Thus the material web disposed around the mandrel has a normal or single layer edge on one side and a double layer on the other by folding the back of the edge on the layer itself, with the double edges on the side facing away from the mandrel. Barrier laminate 108. In the winding mandrel, the double edge with the outward facing barrier laminate 108 is now first applied out of one side of the mandrel, and then the single layer edge area is mandrel with the barrier laminate 108 facing the mandrel from the other side of the mandrel. Placed around, its barrier laminate 108 is placed in and welded to the barrier laminate 108 of the bent edge. The result of this manufacturing variant is likewise a folded joint as shown in FIGS. 14, 15, 19 and 21-23.

In the next step, the inner kraft paper layer 103 is disposed around the barrier layer 102 and is also preferably supplied as web material in the longitudinal direction of the mandrel of the winding machine and further moved in the longitudinal direction of the mandrel. The two edges of the inner kraft paper layer 103 are formed around the barrier layer 102 located in the mandrel so that these edges opposite the mandrel and the barrier layer 102 located in the mandrel are now of the inner kraft paper layer 103. Surrounded by web material. As described, the edges of the inner kraft paper layer 103 are preferably overlapped with each other and they are glued to each other. The inner kraft paper layer 103 has a glue therein, for example by applying an adhesive during the supply of web material, in which case the inner kraft paper layer 103 is attached to the kraft paper layer 107 of the barrier layer 102. When fitted or pressed, glue is distributed over the entire area between layers.

In the following steps (from 0 up to 3 preferably) the central kraft paper layers 104 are arranged continuously around the inner kraft paper layer 103, in which case they are also preferably in the longitudinal direction of the mandrel of the winding machine. It is supplied as web material and moved in the longitudinal direction of the mandrel. Two edges of each central kraft paper layer 104 are formed around the kraft paper layer 103 already located on the mandrel so that these edges meet at the other side of the mandrel and the kraft paper layer 103 located on the mandrel is now web Surrounded by materials. As described, the edges of each central kraft paper layer 104 preferably overlap each other and are bonded together. Each central kraft paper layer 104 has a glue therein, for example by applying it during the supply of web material, in which case the central kraft paper layer 104 is fitted to the kraft paper layer 103 already located on the mandrel. When pressed or pressed the glue is distributed over the whole area between the layers.

In the next step, the outer or kraft paper layer 105 is formed around the outer kraft paper layers 103 and 104 already wound around the mandrel, and is also preferably supplied with web material in the longitudinal direction of the mandrel of the winding machine. It is further moved in the longitudinal direction of the mandrel. The two edges of the outer kraft paper layer 105 are formed around the kraft paper layers 103 and 104 that are already located in the mandrel so that these edges meet on the other side and the kraft paper layers 103 and 104 that are already located in the mandrel are now attached to the web material. Surrounded by As described, the edges of the outer kraft paper layer 105 preferably do not overlap one another so that they meet at the joint. The outer kraft paper layer 105 has a glue therein, for example by applying it during the supply of web material, in which case the outer kraft paper layer 105 is fitted or pressed against the kraft paper layers 103 and 104 wound thereunder. When glue is distributed over the whole area between the layers.

As shown in FIG. 19, the outer kraft paper layer 105 may preferably already have an outer barrier layer 106 such that it has a liquid resistant or liquid water repellent outer side, ie a laminate or web material coated on one side. Can be supplied as. For example, the outer kraft paper layer 105 may have waterproof or moisture-tight printing.

If the outer kraft paper layer 105 does not yet have a liquid resistant or liquid water repellent outer side during feeding, it may be provided at or after the winding machine. For example, a liquid resistant or liquid water repellent film or laminate can be applied around the outer kraft paper layer 105 in the winding machine. For example, after winding, the molded hollow cylinder can be sprayed or printed with a liquid resistant or liquid water repellent material, in particular paint. When a liquid resistant or liquid water repellent film or laminate is applied around the outer kraft paper layer 105 with a winding machine, such film or laminate may be a welded plastic surface on the plastic side to tightly surround the outer kraft paper layer 105. . In the case of a film, as shown in FIG. 21, simple superposition is sufficient. In the case of laminates made of film and thin printing or label paper, for example, the folded seams can also be provided thereon, as shown in FIG. As shown in FIG. 23, the barrier layer 106 may also be applied over the outer kraft paper layer 105 in the form of a rigid print or label layer at least on its outside, which may then be used as an example. For example, it is sealed with a glued-on strip 109 in the adjacent region of its two edges.

If the outer kraft paper layer 105 already has a liquid resistant or liquid water repellent outer side during feeding, then in the next step the joint area of the outer layer is preferably on a winding machine, for example as a liquid or as illustrated in FIG. 19. Likewise, the strip 109 is sealed by applying a liquid resistant or or liquid-water repellent material, in particular in the form of an adhesive tape.

The outer joint of the outer paper or kraft paper layer 105 or of an additional layer disposed thereon can thus be designed as a folded joint and as a simple overlap or joint (butt joint joint). The butt joint seam may be sealed by hot melt, stripe or tape or sealing liquid, where such means are preferably applied in a winding machine after winding the outermost layer and before cutting the individual hollow cylinders. The stripe or tape may be self adhesive or may be present as a plastic strip, in particular a PE strip, which is fixed by ultrasonic welding.

Preferably, as shown in FIG. 25, hot melt 112 is applied to a winding machine having a nozzle 113 in a paper tube located on the mandrel and moves past the nozzle 113. Preferably, the nozzle is directed perpendicular to the gap of the butt joint seam 114 running in the longitudinal direction of the outermost layer of the paper tube applied to the winding machine. The nozzle 113 may be cylindrical or rectangular in cross section and may have a straight or even opening surface.

Preferably, however, the nozzle opening surface has a concave shape, as seen in the circumferential direction of the paper tube, ie adapted to the cylindrical shape of the tube, and the opening surface of the nozzle preferably has a uniform distance from such a tube. .

The hot melt 112 is preferably applied directly to the winding machine after winding the outermost layer, where the outermost layer is already a rigid outer barrier layer 106 or has such a layer. Hotmelt 112 is applied to seal the absorbent cut edges of the outermost layer or to seal the underlying kraft paper layer 103 or 104 along the butt joint seam 114. Preferably, the outer layer is formed from an absorbent material, in particular paper or kraft paper, which is provided on its exterior, for example, laminated with a moisture resistant film or coated with a moisture resistant material. The gap of the butt joint joint 114 preferably has a range of 0.5 mm or more and 4 mm or less. The hotmelt 112 is preferably applied in the form of a strip protruding across the gap of the butt joint seam 114, wherein the width of the strip of the hot melt 112 is preferably at least 1 mm, in particular butt joint seam 114. At least 2 mm wider than the width of the gap is preferably. For example, the width of the butt joint seam 114 is 3 mm wide and the hot melt strip is 6 mm wide. The hot melt 112 is applied, for example, heated at 160 ° C. to 190 ° C., and cured by cooling until the individual cylinders are cut from the mandrel 23 of the winding machine. It may preferably be supported in the form of a cooling device, for example a blower. 27 shows an exemplary can shell 101 according to the present invention with a hot melt seal of the butt joint seam of the outermost layer. The kraft paper layers 103, 104, the outer barrier layer 106 and the sealed butt joint seams of the outer layer directly bonded by an anaconda seal of the folded seam or barrier layer 102 give rise to a particularly preferred can body. This is because sealing the butt joint seam with an adhesive creates a very flat or homogeneous outer circumference of such a can. The film formed on the outer barrier layer 106 is, for example, only 0.05 mm to 0.1 mm thick by adhesive or hot melt 112. Instead of the outer kraft paper layer 105 comprising the barrier layer 106, it is also possible to use different paper or cardboard materials, preferably those containing or made from recycled paper or fiber materials.

Figure 24 shows a further outer layer sealing variant according to the invention, wherein the outer kraft paper layer 105 has an outer barrier layer 106 in the form of a film, where the kraft paper layer 105 and the film are as laminates. It is present and thus fed together to the winding device as the material web. The film layer is designed to be longer in the cross direction of the material web than the kraft paper layer 105 such that the edge of the film layer protruding on one side lies at the other non-protruding edge of the film layer. In this case, the protruding edges of the film layer may be melted or welded on the film layer which does not overlap with the kraft paper, or the adhesive may be applied to the underside of the overlapping area, in particular activatable, to bond the film layer to itself. Especially heat activatable adhesives can be applied.

After the layers have been wound and joined into the tubular body, the individual hollow cylinders are cut from the mandrel using known cutting machines.

The individual hollow cylinders are then bent at the two ends of the edge region.

This bending is preferably carried out in the length range of 5 mm, wherein the outer edge is bent outward by 2.5 mm. From the outer edge, the bent area is preferably merged into an unbent shell area along a circular path with a radius of 3 mm to 4 mm, in particular 3.3 mm to 3.5 mm.

Cut or already bent edges are preferably provided with a sealing liquid so that their absorbing capacity is reduced by moisture. This is preferably done by applying such a sealing liquid during the bending process. Alternatively, sealing of the cut edges can be performed by applying a tape or shrink tube.

The bent and finally sealed hollow cylinders are then transferred to the can closing machine so that one end, preferably the lower end, of the hollow cylinder is closed with a first closing element, for example the first bottom element 4. The bottom element 4 is preferably an aluminum bottom element of a conventional aluminum can, which has at least about the same volume or diameter as the current can.

The medium, in particular the carbonated beverage, is then filled in a bottom closed hollow cylinder, preferably in an amount of 0.25 liters.

The filled hollow cylinder is then closed from the top with a second closing element 25, for example a cover element 5. The cover is preferably an aluminum cover of a conventional aluminum can, which has at least about the same volume or diameter as the current can.

Closure and charging is preferably performed in a clocked plant at a throughput of 80,000 cans per hour.

Preferably, 40,000 can bodies are made per hour in the winding machine, which means a speed of about 1.5 m / s of the finished pipe in the direction of the winding mandrel. The desired process output of 80,000 cans per hour can be achieved by mirroring the machine, with the flanged can bodies from both machine units being brought together in front of the can bottom sealer.

Preferably, the can shells 2 of the invention resulting from a slower winding system can be closed in the same faster closing and filling plant together with conventional aluminum can shells, more preferably with the same floor elements. With covers, without retooling or time interruption. This means that the speed of the winding system is no longer critical to the process and the filling plant can operate independently of the overall process performance.

The composite candle and conventional aluminum cans according to the invention can be filled in batches or alternately in the same plant so that the lower production rate of a single winding plant is compensated by the production of conventional aluminum cans. For example, the plant can produce 40,000 cans per hour and 40,000 aluminum cans per hour so that the plant can continue to produce at the same time two production lines, eco-friendly composite cans and proven aluminum cans.

The need of the composite can shells according to the invention can be met exactly and the remaining capacity for standard cans is used, which is because the sale of the composite cans according to the invention does not initially lead to the full utilization of existing filling plants. Particularly advantageous. The simultaneous or sequential use of the filling plant according to the invention for a candle according to the invention and a candle according to a conventional aluminum candle is thus only gradually replaced by the composite candle up to an increasing rate where the aluminum cans can continue to be produced. As such, the additional suppression threshold for product conversion is further reduced.

10 to 12, two pipe sections 28, can shells 101 made of a composite material consisting primarily of paper or cardboard material and can shells 117 made of aluminum or tin plate are optionally filled and sealed. The filling and sealing plant according to the invention is shown. The can filling and sealing plant according to the invention comprises a first supply device 115 provided with can shells 101 made of a composite material, and a second supply device 116 provided with conventional can shells 117. ) As shown, the feeders 115, 116 may be linear feeders, such as conveyors and the like. The supply devices 115, 116 may also be robots or other handling devices that lift the can shells 101, 117 into the transport device 119. Composite can shells 101 and conventional can shells ( In the case of a robot or other handling device that alternately places 117 on the conveyor 119, the feeders 115, 116 may also be implemented as one device to perform both tasks.

When feeding together with linear conveyors they are preferably controlled by at least one setting element 118, which can be configured by which can shells 101, 117 from which supply device 115, 116 the system is located. Control the arrival of the transport device 119 or in which order and / or ratio the can shells 101, 117 arrive at the transport device 119.

Preferably, the supply device 115 for can shells 101 made of composite material is connected directly to the manufacturing apparatus of these can shells 101, with the buffer zone advantageously placed above the setting element 118. Can be. Less preferably, the can shells 101 may be transferred and stored in a batch from the manufacturing apparatus to the feeder 115. The can shells 101 are particularly preferably can shells 101 according to the invention according to alternative embodiments of FIGS. 13 to 24 and in particular of FIG. 27.

From the feeder 116, prefabricated conventional can shells 117 made of aluminum or tin plate are supplied from the stock warehouse, since their production at the time of filling is virtually impossible.

The can shells 101, 117, which have been transferred from the supply apparatus 115, 116 to the transport device 119 at a selectable ratio, are preferably transported by this transport device 119 through all stations of the system.

The first station is the first closing device 30, in which case the first closing elements, for example the bottom element 4, are attached to the open can shells 101, 117 on both sides. Attachment of the closing elements is carried out with a pressing device 32, which presses the closing elements with can shells 101 and 117 in a pressure-tight manner, respectively.

The can shells 101, 117 with one end closed are conveyed to the second station by the transport device 119, and the filling device is placed so that the closed end of the cans lies below, where the can shells 101, 117 are Is turned on the way. The turning device is not shown.

The filling device is preferably a carousel 33, in which a plurality of candles 101, 117 closed on one side are particularly preferably a carbonated beverage, in particular a strong carbonated beverage such as coke or other carbonated soft drinks. It is filled in a nested manner.

From the filling device, the transport device 119 transports the filled can shells 101, 117 to a third station which is an additional closing device 34.

Using the second closing device 34, the second closing elements, for example the covers 5, are attached to the filled can shells 101, 117 which open on one side. Attachment of the closing elements is carried out with a pressing device 35, which presses the closing elements with can shells 101 and 117 in a pressure-tight manner, respectively.

The first closing element may be the bottom element 4 and the second closing element may be the cover 5 and vice versa.

Transport device 128, 129 in which the second closure device 34 is followed by cans with can shells 101, preferably made of cardboard or paper material, and cans with can shells 117, made of aluminum or tin plate. Is switched on. Alternatively, such cans may also be removed from the transport device 119 by a robot or other handling device. Thereafter, different cans are each stored, sorted or packaged for further transportation.

Alternatively, the packaging can also be carried out together in a mixture of two types of cans, for example arranged in a transport container. Advantageously, to assure a suspicious consumer of new packaging, it can be packaged in known plastic wrap or cardboard containers for cans such as, for example, three conventional aluminum cans and one composite shell can. have. Due to the selectable mixing ratio of the different cans this is for example 3: 1 for four packs or 5: 1 for six packs or 23: 1, 20: 4 or 18: for pallets. Ideally it can be adapted to common package sizes as just described with 6.

The mixing ratio in which the can shells 101, 117 are continuously processed in the plant is also for example 24 composite can shell 101 alternating with 240 existing alumina shells, or 40,000 composite can shell 101 with 40,000 It may be performed in larger blocks of different can shells 101, 117, such as alternating with alumina shells.

The smaller block size of the composite can shells 101 (continuous number of one type of can shells) depends on the speed of the winding device without the large storage of the can shell 101 between the winding device 101 and the filling plant. It is preferred because it can be filled. Preferably, the mixing ratio of the composite canshells 101 to alumina shells is 1: x, where x is greater than or equal to 1 and the block size of the composite can shells 101 is preferably less than 10, particularly preferably Is 1. It is particularly advantageous in the continuous feeding and filling of the composite can shells 101, whereby the winding device connected to the filling device can be operated continuously, before the already applied glue hardens or applicators or nozzles attach the layers of the hollow cylinder. Longer stopping of the winding device becomes a problem because it will prevent them.

Preferably, only one type of closure element is used in the closure devices 30, 34 for all types of can shells 101, 117 of the same size.

Less preferably, each self closing element at the required mixing ratio is provided for can shells 101 made of cardboard or paper composite material and can shell 117 made of aluminum or tin plate. An advantage of this is that a closure element for can shells 101 of cardboard or paper composite material, which is specifically adapted for this material, can be used.

Instead of providing a closing element with one feeder unit as shown, there may be less preferably two feeder units, one feeder unit being a closing element for can shell 101 made of cardboard or paper composite material. And another closure element provides a closure element for can shells 117 made of aluminum or tin plate. This applies equally to crimping devices 32 and 35, which may be advantageous for different closing elements or can shells 101, 117 or for different crimping devices. The different crimping devices 32, 35 can preferably be positioned continuously on the transport device, with each crimping device 32, 35 closing only the can shells 101, 117 for what is designed.

Less preferably, merging or splitting of different can shells 101 can also occur only immediately before or after the filling device 33. This is because can shells 101 made of cardboard or paper composite material, which are already closed at the bottom, filling device 33 and / or switch element 127 for individual closure in its closing device. From the supply device 115 to the transfer device 119 immediately before being able to discharge the filled can shells immediately after the filling device 33.

Example 1

In the particularly preferred layer structure of FIG. 27, beverage cans are prepared having a height of 134 mm and an outer diameter of 52.4 mm and a filling volume of 250 ml of carbonated beverage. As paper or kraft paper layer 105, a paper layer 105 with low resistance to tearing, wood-free paper, specifically Lumiflex ^™ 110 gsm Stora Enso AG Is used, which has a PE coating on the outside of the can later. The beverage cans are sealed at the top and bottom with standard bottoms with covers of aluminum cans with standard closure equipment.

The layers used and the resulting layer structure are specified in Table 1 below.

Grammage thickness Tensile strength MD
lso 1s24-2 Tensile strength CD
lso 1s24-2 Barrier Laminate 108 45 g / m² 45 μm Not determined Not determined Kraft Paper Floor 107 60 g / m² 82 μm 7.0 kN / m 3.5 kN / m Kraft Paper Floor 103 125 g / m² 160 μm > 10 kN / m > 5 kN / m Kraft Paper Floor 104 125 g / m² 160 μm > 10 kN / m > 5 kN / m Paper layer 105 110 g / m² 101 μm 7.3 kN / m 0.7 kN / m Outer barrier layer 106 (PE) 15 g / m² 15 μm Not determined Not determined Total layer structure Approx. 500 g / m² About 600 ㎛ Not determined > 23 kN / m

The tensile strength MD (Machine Direction) represents the tensile strength of the kraft paper in the longitudinal direction of the can shell 101, and the tensile strength CD (Cross Direction) represents the tensile strength of the kraft paper in the circumferential direction of the can shell 101. It can be seen that the conventional paper of the paper layer 105 used in particular in the cross direction (CD) has a significantly low tensile strength.

The gram of the overall layer structure of the can shell 101 is increased compared to the sum of the individual layers due to the glue application of 18 g / m² per layer of glue. Glue applications total 54 g / m² due to the three total surface layers of the glue.

As the barrier laminate 108, a laminate having a structure of a 25 μm thick PE plastic film, a 7 μm thick aluminum foil, a 3 μm thick Surlyn bonding agent, and a 15 μm thick PE plastic film are used.

In the case of the can shell 101, the tensile strength measurement in the circumferential direction of the can shell is performed by cutting into 15 mm wide strips. In this dimension, the average tensile strength is measured at 374.3 N / 15 mm, which corresponds to a tensile strength of 25 kN / m.

The cans thus prepared are suitable for the storage and transportation of carbonated beverages.

A particularly preferred layer structure of the container according to the invention thus has an inner barrier layer 102 made of barrier laminate 107 and kraft paper layer 108, with the folded seam extending in the longitudinal direction of the can and two above it. The kraft paper layers 103 and 104 each have a reduced thickness at least one edge in the paper layers 103 and 104 having overlapping seams running in the longitudinal direction, and above the kraft paper layers 103 and 104, Along the wound layer or along the cardboard material, which is sealed with hot melt, with a gap to form a butt joint seam with an outer barrier layer 106 extending longitudinally of the can, in this case their kraft paper surface The kraft paper layers 103, 104 with the adhesives are in particular directly bonded to each other and adhere to the base layer and the overlapping layer.

Advantages of the candle according to the invention are recyclability and good ecological assessment. Since the cans of materials used are similar to plastic coated cardboard packaging, aluminum parts, paper layers and plastic films can be separated from each other and separated and sorted for recycling by similar known dissolution methods. In particular, the high percentage of renewable parts, especially in paper form, can be advantageous over cans made of aluminum and / or plastic. Ecological assessment of this is better than conventional aluminum candles.

r Energie- und Umweltforschung HeidelbergGmbH는 현재 캔에 대해 225kg/1000 l에 해당하는 CO₂를 330㎖로 결정했으며, 330㎖의 알루미늄 캔에 해당하는 CO₂는 350㎏/1000l로 결정되었다.ifeu-Institut f

r Energie- und Umweltforschung HeidelbergGmbH has determined the CO ₂ corresponding to 225kg / 1000 l for the current in the can 330㎖, CO ₂ for the aluminum can of 330㎖ was determined 350㎏ / 1000l.

FIG. 28 shows the current of the can shell 101 in the longitudinal portion via the folded seam of the barrier layer for use in Can 1 containing a liquid and / or gaseous medium which may have a positive pressure or may occur during transport or storage. Indicative of an unclaimed variant, the cylindrical can shell 101 consists mainly of paper or cardboard material and comprises at least two wound layers and is closed at the bottom with a cover element 5 at the top with a bottom element 4 at the bottom, Can 1 withstands an internal pressure of at least 5 bars, wherein the innermost layer of can shell 101 consists of a straight wound barrier layer with folded seams extending longitudinally of can 1, where the barrier layer Is a laminate made of an inner diffusion-tight film or inner diffusion-tight barrier element 108, a central paper or preferably a kraft paper layer 107 and an outer plastic layer 115, At least one additional wound layer made of paper or cardboard material with a secondary plastic layer 115 is present around the barrier layer of the can shell 101, and the paper or paper with the adjacent plastic layers 115 of the barrier layer 102. Additional wound layers made of cardboard material are welded directly to each other.

In the case of a split application for this variant, the previous paragraph may replace claim 1, so that the dependent claims replace the adhesive or glue by joining the layers with two adjacent welded plastic layers 115. Can be adapted.

An additional wound layer of paper or cardboard material with an inner plastic layer 115 may also have an outer plastic layer 115.

Furthermore, there may be up to two additional layers of paper or cardboard material, preferably with the inner plastic layer 115 and / or the outer plastic layer 115 respectively, in which case the adjacent plastic layer 115 of the layers is Are welded together.

The further wound layers of paper or cardboard material with their plastic layer 115 may in turn have longitudinal seams, and preferably have a reduced thickness in their overlapping areas. The outermost layer may have butt joint seams again with the gap properly sealed.

The paper or cardboard material of one or more or all layers may preferably be kraft paper or paper or cardboard material having comparable tensile indices MD (machine direction) and CD (cross direction).

Claims (27)

In a can containing liquid and / or gaseous medium,
The medium may have or create a positive pressure during transport or storage, and the cylindrical can shell 101 of the can may consist primarily of paper or cardboard material and have at least two windings. Is closed at the bottom with the bottom element 4 and the top with the cover element 5, the can 1 having an internal pressure of at least 5 bar. Enduring)
The innermost layer of the can shell 101 consists of a straight-wound barrier layer 102 having a folded seam extending in the longitudinal direction of the can 1, The barrier layer 102 is a laminate made of an inner diffusion-tight film or an inner diffusion-tight barrier element 108 and an outer kraft paper layer and is made of paper or cardboard. At least one additional winding layer made of material is present around the barrier layer 102 of the can shell 101, and the adjacent cardboard or paper surfaces of the barrier layer 102 and the paper or cardboard material The winding layers, which are made of a can, are characterized in that they stick directly to each other and in particular adhere to each other. According to claim 1,
A can, characterized in that an adhesive, in particular glue, is introduced into the back side of the folding seam in the curved area of the barrier layer (102). The method according to claim 1 or 2,
The barrier layer 102 is a prefabricated laminate of the inner diffusion-sealing barrier laminate 108 and the outer kraft paper layer 107, the barrier layer 102 having a layer thickness from 0.098 mm to 0.145 mm, The kraft paper layer 107 of the barrier layer 102 has a layer thickness of 0.065 mm to 0.090 mm, and the diffusion-sealing barrier film or the diffusion hermetic barrier laminate 108 has a thickness of 0.033 mm to 0.055 mm. A can, characterized in that it has a layer thickness. The method according to any one of claims 1 to 3,
At least one winding kraft paper layer 103, 104 is externally attached above the barrier layer 102, and its inner kraft paper surface is attached to the kraft paper surface of the barrier layer 102 on which it is attached. A can, which is characterized in that it adheres and adheres in particular to the outer kraft paper surface thereof, which adheres to and particularly adheres to the cardboard, paper or kraft paper surface of another winding layer made of paper or cardboard material. The method of claim 4, wherein
The first winding kraft paper layer 103 is attached to the first winding kraft paper layer 103 externally, and the inner kraft paper layer thereof is mounted on it. Clinging to and particularly adhering to the kraft paper surface, wherein the outer kraft paper surface thereof is clinging and especially adhering to the cardboard, paper or kraft paper surface of another winding layer made of paper or cardboard material Can made. The method according to claim 4 or 5,
The first kraft paper layer 103 and / or the second kraft paper layer 104 may include at least one edge region that does not overlap itself or has a reduced thickness in the overlap region with itself. The can which is characterized by having. The method according to any one of claims 1 to 6,
The innermost layer of the can shell (101) is characterized in that the moisture-resistant outer barrier layer (106) present as a coating or film material. The method of claim 7, wherein
The outer barrier layer 106 of the can shell 101 is present as a film coated or laminated onto a paper or cardboard material used to wind the outermost layer of the layer structure, the paper or cardboard material thereof A butt joint seam with itself and the gap of the butt joint seam is sealed by the film itself being coated or laminated, a strip bonded or welded, a sealing liquid, or a hotmelt The can which is characterized by being. The method of claim 7, wherein
The outermost layer of the can shell (101) is characterized in that the moisture resistant outer barrier layer (106) applied to a single can shell (101) already cut in the form of a coating or in the form of a film or shrink film. The method according to any one of claims 1 to 9,
The thickness of the can shell 101 over the circumference of the can is constant or has a deviation including at least one elevation, and the can shell 101 on the location of the largest height. The thickness of the can, characterized in that up to 160% of the thickness of the remainder of the can shell 101 having a constant thickness and the largest height in absolute terms is up to 290 μm. The method according to any one of claims 1 to 10,
Wherein each layer thickness of at least two of the further kraft paper layers (103, 104, 105) is in each case selected from the range of 140 μm to 175 μm. The method according to any one of claims 1 to 11,
The can shell (101) in said region without height has a thickness from 400 μm to 700 μm, in particular from 540 μm to 660 μm. The method according to any one of claims 1 to 12,
The can shell 101 has a height in the region of the folding seam, and the can shell 101 has a thickness in the region of the height, which is from 110% to 160% of the thickness in other regions. , Cans. The method according to any one of claims 1 to 13,
The paper material of the kraft paper layer 107 and the kraft paper layers 103, 104 has a tensile index (MD) greater than 80 Nm / g and a tensile index (CD) greater than 40 Nm / g. Characteristic can. The method according to any one of claims 1 to 14,
At least one of said further kraft paper layers (103, 104) comprises an area which is longitudinally wound and overlaps said butt joint or itself in said longitudinal direction of said can shell (101). The method according to any one of claims 1 to 15,
The can, characterized in that it can withstand an internal pressure of at least 6 bar, in particular at least 10 bar. The method according to any one of claims 1 to 16,
Wherein said medium is a carbonated beverage. The method according to any one of claims 1 to 17,
The bottom element 4 and the cover element 5 are suitable for sealing can shells made of aluminum and / or suitable for processing in systems for sealing can shells made of and / or made of aluminum. A can, characterized in that the cover elements. In the can manufacturing method according to any one of claims 1 to 18,
In a first step the can shells are made of a continuous winding machine which is applied on a winding mandrel on which the individual layers are connected and connected in series with each other, the barrier layer 102 extending in the longitudinal direction. The folding seam is provided at the winding and the resulting tube 27 is then cut into individual cylindrical hollow bodies that open on both sides,
In the second step the two open ends of the cylindrical hollow body are bent outwardly so that the ends have a circular cross section having a larger diameter than the remaining cylindrical hollow bodies,
In a third step the lower end of the cylindrical hollow body is closed by a crimping device 22 with a bottom element 4,
In a fourth step the closed hollow body is filled with the medium using a filling device 33,
The hollow body, which is closed at the bottom in the fifth step, is closed by the crimping device 24 at the top with the cover element 5,
Wherein said fourth and fifth steps, and preferably also said third step, are carried out in a filling plant suitable for filling and closing known aluminum cans. The method of claim 19,
In the first step an adhesive, in particular a glue, on the winding machine 111 is optionally applied with a nozzle in the area of the folding seam of the continuously wound barrier layer 102, the two of the folding seam being The kraft paper layers (107) are characterized in that they stop in contact with each other. The method of claim 19 or 20,
In the first step an adhesive, in particular a hotmelt 112 in the winding machine is selectively applied to the nozzle 113 in the area of the longitudinal seam of the outermost layer applied in the winding machine, resulting in A method of making a can, characterized in that the longitudinal seam is sealed by the adhesive, in particular hot melt (112), before the resulting tube (27) is cut into individual cylindrical hollow bodies which open on both sides. The method according to any one of claims 19 to 21,
In any case after the first or second step and before the third step, the cut edges of the hollow body that open on both sides absorb liquids and / or gases at their cut edges. Characterized in that it is sealed to reduce the capacity of the paper or cardboard layers. The method according to any one of claims 19 to 22,
The winding system and a machine for processing the two open ends of the cylindrical hollow body are provided at a place to fill so that the manufacture of the cans is made without long transport routes and without large stockpiling of can shells. The manufacturing method of the can characterized by the above-mentioned. The method of claim 23, wherein
And the can shells are fed from the machine to process the two open ends of the cylindrical hollow body without intermediate storage of the filling system to the transport device. The method according to any one of claims 19 to 24,
Method for producing a can, characterized in that the filling plant is offset or alternating in time for filling the cans 1 according to any one of claims 1 to 18 and existing aluminum cans. . The method of claim 25,
The filling system comprises a transport device for transporting the can shells through the plant, wherein the can shells made of composite material and the can shells made of aluminum alternately fill the different cans at a constant rate, simultaneously A method of making a can, characterized in that being transported from a device. In a plant for filling and closing the candle,
The plant has a feeding device 115 for can shells 101 which consists mainly of paper or cardboard material,
The plant has a feed device 116 for can shells 101 consisting mainly of aluminum or tin plate,
The plant has a transport device 119 for transporting can shells 101, 117,
The plant has at least one filling device 33 for filling closed can shells at one end 101, 117,
The plant comprises at least one closure device for closing at least one of the ends of the can shells 101, 117,
The can shells 101 mainly made of paper or cardboard material and the can shells 117 made mainly of aluminum or tin plate are conveyed through the plant in at least sections by the same transport device 119 and are thus identical Characterized in that it is filled by a filling device (33).

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